The part which says in every day language the term low voltage refers to below 50v
I suspected that, but have to wonder what part of the "world of everyday language" you live in! Go into any high street store which sells light fittings or lamps/bulbs and ask where you can find the "low voltage" ones, and I'd be extremely surprised if you were directed to 230V products!
... and it's not only 'the general public'. Look at the websites of electrical suppliers such as TLC and you will find sections for "Low Voltage" lights, which is where you will find 12V ones.
We've discussed this issue many times here and, as a result, over the years I have asked many people I come into social contact with what they understand by "low voltage", and I don't think a single one has given me the 'correct' (IEC) answer!
Kind Regards, John